This invention relates to a support base or a frame for a large machine or other object, and more particularly to a support base for a machine such as a so-called rotary sand/casting separator. Although described with particular reference to that application, those skilled in the art will recognize the wide applicability of this invention.
In providing a suitable support base for a rotary sand/casting separator or the like, it is usually necessary that the support uniformly and precisely support the machine in predetermined position and alignment so as to ensure that the machine operates in its intended manner. In particular, a rotary sand/casting separator includes an elongate horizontal cylinder which is rotated about its longitudinal centerline by a drive motor. The cylinder is hollow and castings along with their molding sand are loaded into one end of the cylinder by means of a conveyor belt or the like. As the cylinder rotates, the castings and sand tumble within the cylinder thus loosening the sand from the castings. A multiplicity of holes are provided in the inner shell of the cylinder and the sand falls through these holes for discharge. The castings are fed forwardly through the cylinder out the opposite end of the cylinder as the latter is rotated. These cylinders may, for example, be quite long (e.g., 288 inches or 7.25 m.) in length and weigh several tons. The cylinder is supported on two or more sets of rotary carrier wheel which engage the lower part of the cylinder at spaced intervals along its length.
Heretofore, the support bases for these rotary sand/casting separators were made as a one-piece weldment. However, the weldment oftentimes became distorted during fabrication and this distortion resulted in a uneven or improper support and alignment for the separator cylinder such when the latter was supported on its carrier wheels that upon operation, the cylinder would tend to become dislocated from its carrier wheel supports or to bind while rotating. This in turn caused excessive loads to be applied to the carrier wheels and to the cylinder thrust bearings. Premature thrust bearing and carrier wheel failures had, on occasion, been observed.
In order to eliminate the distortion from the base it was necessary to straighten the weldment in a large press or to stress relieve the weldment after welding. However, both of these operations are considered to be too costly and time consuming to be a practical solution.
Reference may be made to U.S. Pat. No. 3,998,262 which discloses a rotary casting/sand separator in the same general field as discussed above.